Circuit breaker

Abstract

An electric switching device of the type having a contact system includes two stationary contact bars and movable contact bridges for interconnecting the bars. To convert the switching device from a circuit maker to a circuit breaker, or vice versa, a control member is provided in the form of a shiftable slide having insulating projections which in one end position of the slide are displaced between one bridge and a contact bar while the other projection is out of the range of movement of the bridges, and in the other end position the other insulating projection interrupts the contact between the other bridge and the assigned contact bar.

I claim: 
     
       1. An electric switching device, particularly a safety switch comprising a housing; and a contact system mounted in said housing and including contact bridges movable relative to said housing, stationary contact bars cooperating with the bridges to close or to open an electric circuit, a contact bridge carrier supporting two contact bridges and including means for resiliently pressing the bridges against opposite sides of the contact bars, and converting means movable relative to said housing between two positions and being engageable with at least a part of the contact system so that in one position the switching device operates as a circuit maker and in the other position as a circuit breaker, said converting means including a center piece mounted on said bridge carrier between said two bridges and being displaceable between a first position in which, in the rest position of said bridge carrier, both bridges are spaced apart from the contact bars so that the device operates as a circuit breaker, and a second position in which one of the bridges is spaced apart from the contact bars and the other bridge is in contact with the contact bars so that the device operates as a circuit maker. 
     
     
       2. An electric switching device as defined in claim 1, wherein the center piece has a rectangular cross section and is eccentrically mounted on a pivot axle. 
     
     
       3. An electric switching device as defined in claim 2, wherein the pivot axle passes through a bore in the bridge carrier which extends perpendicularly to the long sides of the bridges, the pivot axle being positively connected to the center piece and being provided at one end thereof with means for adjusting its angular position. 
     
     
       4. An electric switching device, particularly a safety switch comprising a housing; and a contact system mounted in said housing and including contact bridges movable relative to said housing, stationary contact bars cooperating with the bridges to close or to open an electric circuit, a contact bridge carrier supporting two contact bridges arranged at both sides of juxtaposed contact bars, the bridge carrier with the bridges being movable between a rest position and an activated position, and converting means movable relative to said housing between two positions and being engageable with at least a part of the contact system so that in one position the switching device operates as a circuit maker and in the other position as a circuit breaker, said converting means including a slider movable relative to said housing in a limited linear path transversely to the path of movement of the bridge carrier and supporting at least two insulating projections so that in one end position of the slider one projection is located between a contact bridge and a contact bar while the projection is located outside the range of movement of the bridges whereas in the other end position of the slider the other projection is located in the path of movement of the other bridge and the one projection is out of the range of movement of the bridges. 
     
     
       5. An electric switching device as defined in claim 4, wherein the slider has the form of a rectangular plate movable parallel to the longitudinal extension of the bridges, the insulating projections extending perpendicularly to a surface of the plate and being staggered relative to each other by the combined thickness of the contact bars with the associated contact pieces. 
     
     
       6. An electric switching device as defined in claim 5, wherein the insulating projections have a wedge-shaped configuration. 
     
     
       7. An electric switching device as defined in claim 5, wherein said plate exceeds in length said contact bridges and each of the projections is arranged at a narrow side of the plate and at opposite sides of the contact bars. 
     
     
       8. An electric switching device as defined in claim 4, said housing being provided with an opening for monitoring and displacing the slider. 
     
     
       9. An electric switching device as defined in claim 8, wherein the slider is provided with index marks indicative of the circuit breaking or circuit making position of the device. 
     
     
       10. An electric switching device as defined in claim 4, wherein the slider is made of an insulating material. 
     
     
       11. An electric switching device as defined in claim 10, wherein the slider and/or the projections are made of an insulating material which is resistant to electric arcs. 
     
     
       12. An electric switching device as defined in claim 4, wherein the slider is provided with means for securing the same in the selected end position. 
     
     
       13. An electric switching device as defined in claim 4, wherein the slider is provided with two pairs of insulating projections arranged at different levels so that in one end position of the slider two projections engage the assigned contact bars in the path of movement of one of the bridges and the other two projections are displaced out of the path of movement of the other bridge. 
     
     
       14. An electric switching device as defined in claim 4, wherein the slider is provided with two pairs of insulating projections arranged at different levels so that in one end position of the slider two projections are displaced out of the path of movement of one of the bridges and the assigned contact bars and the other two projections are placed in the path of movement of the other bridge.